A newly proposed carbon allotrope called GPG combines graphene layers bridged by p-phenyl groups, engineered to modulate interlayer spacing and π-electron delocalization to improve ion migration and electron mobility.

Structural verification using ACTEM, SSNMR, AFM, and Raman confirms GPG on high-quality graphene precursors, noting defects and an interlayer spacing around 0.59 nanometers.

GPG enables ultra-fast ion diffusion, with AlCl4− diffusing about ten times faster than in graphite and very rapid K+ migration; a full AlCl3-EMIC||GPG system demonstrates strong fast-charging potential.

DFT and phonon analyses reveal distinct vibrational signatures for H-type and Z-type GPG, linking interlayer coupling to changes in phonon density of states and potential thermal transport properties.

The p-phenyl bridges widen the interlayer gap in GPG, reducing ion migration barriers relative to traditional multilayer graphene and enabling faster ion transport, with analyses suggesting tunable interlayer interactions through the bridging groups.

Two stable GPG models, Z-type and H-type, were identified via DFT/MD, with H-type predicted as most stable and Z-type easier to form; both exhibit non-zero density of states at the Fermi level, indicating enhanced conductivity over graphene.

GPG pyrolyzed at 1600°C (GPG-p-1600) achieves very high in-plane mobility and conductivity, while potassium-ion batteries using GPG as the negative electrode show high-rate tolerance and long cycle life with near-constant capacity and high Coulombic efficiency.

Scalable kilogram-scale synthesis is demonstrated through a diazotization-reduction route from graphene oxide or exfoliated graphene, yielding GPG precursors that can form flexible films or powders, with 3D imaging revealing a porous macroscopic morphology.

Overall, GPG presents a scalable, controllable platform combining high in-plane conductivity, reduced interlayer van der Waals forces, expanded spacing, and exceptional fast-ion transport, with promising applications in batteries, sensors, and catalysis, subject to further validation.